NFE_RXFILTER
NFE_WRITE(sc, NFE_RXFILTER, val);
filter = NFE_READ(sc, NFE_RXFILTER);
NFE_WRITE(sc, NFE_RXFILTER, filter);
val = NFE_READ(sc, NFE_RXFILTER);
NFE_WRITE(sc, NFE_RXFILTER, val);
val = NFE_READ(sc, NFE_RXFILTER);